import React from 'react'; // react的核心库 就是react.js
import ReactDOM from 'react-dom'; // react的dom系统 react建议使用jsx编码方式
import './index.css';
import App from './App'; // 入口组件 
import reportWebVitals from './reportWebVitals';
// index.js相当于vue中的main.js
// render渲染函数
ReactDOM.render(
  // StrictMode 启动react严格模式
  <React.StrictMode>
    <App />,
  </React.StrictMode>,
  document.getElementById('root')
);


// new Vue(h => (app)).mount('#app')
// If you want to start measuring performance in your app, pass a function
// to log results (for example: reportWebVitals(console.log))
// or send to an analytics endpoint. Learn more: https://bit.ly/CRA-vitals
reportWebVitals();
